The preparation and serving of large numbers of meals in an institutional setting has long posed a variety of problems. The ability to serve palatable meals with the various dishes being served at optimum temperature often conflicts with efforts to make service of the meals easier, more efficient and less manpower intensive.
The preparation, storage, rethermalization and service of a large number of meals has evolved through several stages. Initially, trays would be filled with foods from various hot or cold storage containers areas just prior to serving and transported to the individual serving areas (such as patient's rooms in a hospital). However, as facilities grew larger, the assembly of trays from a centralized area became very difficult if not impossible. Frequently in such a system, the time between tray assembly and service grew larger which resulted in food being served at an unpalatable temperature or with spoilage occurring.
Early attempts to overcome such problems resulted in the development of storage carts having separate hot and cold storage compartments. These separate compartments would either be heated or cooled or would be well insulated in order to maintain the food at a desired temperature. In use, food would be loaded into separate hot and cold storage compartments in a central food preparation area. The carts could then be transferred to various assembly locations. The individual meals could then be assembled on trays as desired and served. However, while such delivery systems did improve the time lag between assembly of the trays and service of the meal, they still required significant man power at serving time because these trays had to be assembled. As a result, frequently the hot food would be maintained hot for an extended period of time and become unpalatable or, if all trays were assembled at once, some food would be cold by the time it was served. Additionally, meal service would be spread out over the time required to assemble the trays.
Another development was a food service system of trays and carts incorporating heating elements which are provided in a refrigerated environment. In this type of system, trays could be pre-assembled whenever desired and loaded into the carts. In the refrigerated environment food would remain cold. At a desired time, the heating elements would be activated to rethermalize the food and to maintain the warm food in a warm condition while not effecting the food which is to remain chilled. After the food had reached a serving temperature the carts could then be rolled to the service locations and the trays served.
However, even these systems have problems. For example, such devices typically provide for a two stage rethermalization program which has a tendency to either overcook the food or take an undesirable long time to reach the desired serving temperature. Typically, these two stage rethermalization cycles heat the food at a first, cooking, temperature and if such temperature is selected to be high enough to rapidly rethermalize the food, the food is often overcooked or scorched. If, on the other hand, the initial heater temperature is low enough to avoid overcooking, the necessary rethermalization cycle is frequently too long.
Additionally, such systems are not capable of adjusting for temperature variations within the refrigerated environment. Stratification of air within the refrigerator will occur because of the tendency of relatively warmer air to rise. This tendency toward stratification is exacerbated by the tendency of warmer air heated by the heaters to rise to the top of the refrigerated compartment. There will also be temperature variations throughout the refrigerator due to the location of registers for the entry of chilled air into the refrigerated compartment. Thus, food at the top of the carts will tend to heat quicker than food near the bottom as the warmer air tends to accumulate at the top of the refrigerator. Also, carts located near the chilled air registers will tend to reach the desired rethermalization temperatures more slowly than carts located in a relatively warmer area of the refrigerator. If not compensated for, the temperature stratification and variation may result in either the overheating of food or the under heating of food depending on the location of the tray in relation to the temperature variations.
Furthermore, such systems have generally had a central controller which, if it malfunctioned, could result in an entire meal not being ready at the desired time. Additionally, the use of a centralized control system has made it very difficult, if not impossible, for these control systems to compensate for the temperature stratification and variation within the refrigerator. Also, such systems rarely provide significant user feedback relating to whether the carts are properly connected in the refrigerator and the overall functioning of the system.